Head-to-Head Comparison

Updated September 5, 2026

Junghans Form A Automatic vs Seiko 5 Sports GMT SSK001

Junghans's dress watch meets Seiko's GMT watch

Quick Verdict

The Seiko 5 Sports GMT SSK001 ($250–$500) delivers Seiko In-House Automatic GMT technology in the tier below the Junghans Form A Automatic ($1,000–$1,500). The 5 Sports GMT SSK001 measures 42.5mm and is rated 100m (10 ATM). The Form A Automatic justifies its premium with Made in Germany heritage and Automatic J800.2 (ETA 2824-2). Both represent excellent choices in the luxury watch category.

View the dossier Seiko5 Sports GMT SSK001$250–$500 Check price

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Junghans

Form A Automatic

$1,000–$1,500

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Seiko

5 Sports GMT SSK001

$250–$500

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Specifications Compared

Feature	Junghans Form A Automatic	Seiko 5 Sports GMT SSK001
Price	$1,000–$1,500	$250–$500
Case Size	39.3mm	42.5mm
Movement	Automatic J800.2 (ETA 2824-2)	Automatic Caliber 4R34 (True GMT)
Caliber Type	Swiss ETA Base, German-Finished	Seiko In-House Automatic GMT
Power Reserve	38 Hours	41 Hours
Water Resistance	50m (5 ATM)	100m (10 ATM)
Crystal	Flat Sapphire with Anti-Reflective Coating	Hardlex Crystal
Case Material	Stainless Steel	Stainless Steel
Origin	Made in Germany	Made in Japan

Category-by-Category Analysis

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Design & Aesthetics

Edge: Draw

Junghans's design language vs Seiko's approach

The Junghans Form A Automatic features a Stainless Steel case at 39.3mm with Flat Sapphire with Anti-Reflective Coating protection. The Seiko 5 Sports GMT SSK001 offers Stainless Steel construction at 42.5mm with Hardlex Crystal. Both represent their brand's distinct design philosophy and heritage.

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Movement & Performance

Edge: Seiko

Automatic J800.2 (ETA 2824-2) vs Automatic Caliber 4R34 (True GMT)

The Form A Automatic runs the Automatic J800.2 (ETA 2824-2) (Swiss ETA Base, German-Finished, 38 Hours power reserve) at 28,800 vph (4 Hz) frequency. The 5 Sports GMT SSK001 uses the Automatic Caliber 4R34 (True GMT) (Seiko In-House Automatic GMT, 41 Hours reserve) at 21,600 vph (3 Hz). The 5 Sports GMT SSK001 offers a longer power reserve.

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Wearability & Fit

Edge: Junghans

39.3mm vs 42.5mm — different wrist presence

At 39.3mm, the Form A Automatic wears more compactly on smaller wrists compared to the 5 Sports GMT SSK001 at 42.5mm. Water resistance differs: 50m (5 ATM) vs 100m (10 ATM).

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Value & Cost of Ownership

Edge: Seiko

Seiko sits in the lower tier

The Junghans Form A Automatic sits at $1,000–$1,500 and the Seiko 5 Sports GMT SSK001 at $250–$500. On the specs that outlast any price: the Form A Automatic uses Flat Sapphire with Anti-Reflective Coating with 38 Hours, against Hardlex Crystal and 41 Hours on the 5 Sports GMT SSK001. Service intervals are typically 5-7 years for both.

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Water Resistance

Edge: Seiko

50m (5 ATM) vs 100m (10 ATM)

The Form A Automatic is rated to 50m (5 ATM) while the 5 Sports GMT SSK001 handles 100m (10 ATM). The 5 Sports GMT SSK001 offers superior water resistance.

Our Verdict

Junghans

Form A Automatic

Choose the Junghans Form A Automatic if you prioritize Swiss ETA Base, German-Finished engineering, Made in Germany craftsmanship, and 50m (5 ATM) water resistance. At $1,000–$1,500, it delivers Automatic J800.2 (ETA 2824-2) with 38 Hours power reserve.

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Seiko

5 Sports GMT SSK001

Choose the Seiko 5 Sports GMT SSK001 if you value Seiko In-House Automatic GMT technology, Made in Japan heritage, and 42.5mm proportions. At $250–$500, the Automatic Caliber 4R34 (True GMT) with 41 Hours power reserve makes it a compelling choice.

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The Bottom Line

The Junghans Form A Automatic and Seiko 5 Sports GMT SSK001 represent two distinct approaches to fine watchmaking — the Junghans bringing Made in Germany tradition while Seiko delivers Made in Japan engineering.

Frequently Asked Questions

For water, the Seiko 5 Sports GMT SSK001 is rated 100 m against 50 m, which is the difference between swimming and diving on one side and splashes on the other. On price, the Seiko 5 Sports GMT SSK001 sits a band lower ($250–$500 against $1,000–$1,500), so it is the cheaper way into the category. Neither is better at everything; the spec table above shows movement, case size, water resistance and crystal side by side so you can weigh what matters to you. We do not test units, so this is the makers' data, not a bench result.

The Seiko 5 Sports GMT SSK001 offers better upfront value, sitting a tier lower at $250–$500. However, the Junghans Form A Automatic may justify its premium with superior finishing, heritage, or resale value.

Both are suitable for daily wear. The Form A Automatic at 39.3mm with 50m (5 ATM) water resistance handles everyday situations. The 5 Sports GMT SSK001 at 42.5mm with 100m (10 ATM) is similarly capable. The Form A Automatic uses Flat Sapphire with Anti-Reflective Coating while the 5 Sports GMT SSK001 uses Hardlex Crystal.

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How This Page Was Made

Our comparisons are generated from a hand-maintained specification database and reviewed under our editorial standards. We use AI tools to assemble pages from that data. We don’t invent specs: every number traces back to the database, and when we correct an entry, the fix is applied site-wide. As an Amazon Associate, The Horologist earns from qualifying purchases.